Waterproof Pool Bottom Drain?

Yes, that particular model I linked to has a locking collar that clamps down but I believe there are a lot of pond guys that are using it in concrete.

They are setting the fixed part of the bezel level with the concrete and then parging their waterproofing layer over the top of it.

Seems to me, there should be some sort of waterproof ring around the body of the drain. Similar to bentonite clay or rubber gasket between a footing and a poured concrete wall, that swells when water contacts it.